Peristaltic pumps are used for feeding fluids in various applications where sanitary conditions apply and where the fluid-carrying tubing has to be changed frequently. Conventionally, peristaltic pumps have a rotor surrounded by a stator or housing with a passageway between the rotor and the interior of the housing for holding a compressible tube which extends at least partially around the rotor. The rotor has radially extending compression units, usually rollers, for occluding the tube to draw fluid into one end of the tube and expel it out another end as the rotor rotates. The force applied by the compression units occludes the tube and also tends to move the tube in the direction of rotation of the rotor so the tube must be firmly secured or clamped at each end of the passageway that it rests in to prevent it from slipping. At the same time, the tube cannot be held or clamped so tight that it interferes with the flow of fluid through the tube. For various applications it has been found necessary to use different sizes (diameters) of tubes and/or tubes that have different wall thicknesses so that means for clamping the tubing in place must be adaptable to accommodate these differences. Additionally, tubes may have different degrees of compressibility or durometers, so that the compressing rollers must be urged radially outward from the rotor with sufficient force to accommodate various degrees of tube compressibility in order to efficiently occlude different varieties of tubes that may be used in the pump. Also since the tubes are likely to be changed often for sanitary reasons, tube replacement should be easy and quick without sacrificing reliability of operation.